The alarming statistic was part of a study conducted by Denver Health, with help from the University of Colorado School of Medicine, Colorado School of Public Health and the University of Utah, which was published in the peer-reviewed Obstetrics & Gynecology.

"It was surprising and concerning to us, because there are data results that cannabis can be harmful to the developing fetus," said Dr. Torri Metz, a high risk obstetrician at Denver Health.

Metz said the study used a "mystery caller approach," with the caller reaching out to 465 Colorado dispensaries. Four-hundred responded.

A researcher, claiming to be eight weeks pregnant, told an employee answering the phone at one dispensary that she was feeling nauseated, and asked if there were any products that are recommended for morning sickness.

The employee replied: "Let me call my daughter, she just had a baby, call me back in five minutes."

When asked why a product was or was not recommended, an employee at another dispensary responded: "Technically with you being pregnant, I do not think you are supposed to be consuming that, but if I were to suggest something, I suggest something high in THC."

When a researcher asked an employee at another dispensary about recommendations on frequency, the employee replied: "In the context of edibles, start with a low dose and see how it works out for you because those types of things would, um, not cross the blood-brain barrier so even if you have got the CBDs and the other good parts of the plant would get in your baby's blood system but the psychotropic properties, the THC molecule, would not get near your baby, so basically would not be getting your baby stoned."

The head of the Marijuana Industry Group told KMGH TV she was surprised by the study results.

Kristi Kelly, the group's executive director said, "What this tells us as an industry is that we have a gap in our 'onboarding process,' in terms of training our dispensary workers to provide not just a good conversation on products, usage and dosing... but it's very important that employees clarify they are not medical professionals and that they also redirect that patient or customers to also have a conversation with their health care professional."